Since I built under Linux, I’m not sure what happened unless stuff ended up in mainsystem.cpp at line one by bad editing.
Clearly there is something wrong with line 1 of that file. You should be able to FIX it yourself.

the first lines should be:

// mainSystem.cpp - main startup and overall control functions

#include “common.h”

As for scriptCompiler, you can remove the warning (I did so already previously) by changing that value to 0 instead of NULL.

Similarly i have already fixed the wordentry warning message, but it won’t harm you to ignore it for now.